The ornamental design for a cassette-shaped wallet, as shown and described.
FIG. 1 is a perspective view of a cassette-shaped wallet showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is another perspective view thereof; and,
FIG. 9 is an operational perspective view thereof showing that a top opening of a compartment is opened by squeezing two opposite sides of the cassette-shaped wallet.